*{
  margin:0;
  padding: 0;
  box-sizing: border-box;
}
body{
  height: 100vh;
  display:flex;
  justify-content: center;
  align-items: center;
  background: radial-gradient(#cef, rgb(25, 52, 107));
}

.slider-container{
  position: relative;
  width: 640px;
  height: 360px;
}

.left, .right{
  width: 60px;
  height: 60px;
  background: white;
  position:absolute;
  top: 150px;
  border-radius: 50%;
  text-align: center;
  line-height: 60px;
  font-size: 20px;
  user-select: none;
  cursor: pointer;
}

.left{
  left: 10px;
}

.right{
  right: 10px;
}